package mylibrary.annotation.DB;

import java.util.ArrayList;
import java.util.List;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;

public class TableCreator {

	public static void main(String[] args) throws Exception {
		
		String[] useClass = {"mylibrary.annotation.DB.Member"};
		for(String className: useClass) {
			Class<?> cl = Class.forName(className);
			DBTable dbTable = cl.getAnnotation(DBTable.class);
			if(dbTable == null) {
				System.out.println("No DBTable annotation in class " + className);
				continue;
			}
			
			String tableName = dbTable.name();
			if(tableName.length() < 1) {
				tableName = cl.getName().toUpperCase();			
			}
			
			List<String> columnDefs = new ArrayList<String>();
			for(Field field:cl.getDeclaredFields()) {
				String columnName = null;
				Annotation[] anns = field.getDeclaredAnnotations();
				if(anns.length < 1) {
					continue;
				}
				if(anns[0] instanceof SQLInteger) {
					SQLInteger sInt = (SQLInteger)anns[0];
					if(sInt.name().length() < 1) {
						columnName = field.getName().toUpperCase();
					} else {
						columnName = sInt.name();
					}
					columnDefs.add(columnName + " INT" + getConstraints(sInt.constraints()));
				}
				if(anns[0] instanceof SQLString) {
					SQLString sString = (SQLString)anns[0];
					if(sString.name().length() < 1) {
						columnName = field.getName().toUpperCase();
					} else {
						columnName = sString.name();
					}
					columnDefs.add(columnName + " Varchar(" + sString.value() + ")" + getConstraints(sString.constraints()));
				}
			}
			
			StringBuilder createCommand = new StringBuilder("Create Table " + tableName + "(");
			for(String columnDef: columnDefs) {
				createCommand.append("\n " + columnDef + ",");
			}
			
			System.out.println(createCommand);
		}
	}
	
	private static String getConstraints(Constraints con) {
		String constraints = "";
		if(!con.allowNull()) {
			constraints += "NOT NULL";
		}
		if(con.primaryKey()) {
			constraints += " PRIMARY KEY";
		}
		if(con.unique()) {
			constraints += "UNIQUE";
		}
		return constraints;
	}
}
